const Question = require('../models/questions')

class QuestionsCtl {
  async find (ctx) {
    const page = Math.max((ctx.query.page || 1) * 1, 1) - 1
    const perPage = Math.max((ctx.query.per_page || 2) * 1, 1)
    const q = new RegExp(ctx.query.q)
    ctx.body = await Question.find({ $or: [{ title: q }, { description: q }] }).limit(perPage).skip(page * perPage)
  }
  async checkQuestionExist (ctx, next) {
    const question = await Question.findById(ctx.params.id).select('+questioner')
    if (!question) {
      ctx.throw(404, '问题不存在！')
    }
    ctx.state.question = question
    await next()
  }
  async findById (ctx) {
    const { fields = '' } = ctx.query
    const selectFields = fields.split(';').filter(f => f).map(f => '+' + f).join('')
    const question = await Question.findById(ctx.params.id).select(selectFields).populate('questioner topics')
    ctx.body = question
  }
  async create (ctx) {
    ctx.verifyParams({
      title: { type: 'string', required: true },
      description: { type: 'string', required: false },
      introduction: { type: 'string', required: false }
    })
    const question = await new Question({ ...ctx.request.body, questioner: ctx.state.user._id }).save()
    ctx.body = question
  }
  async update (ctx) {
    ctx.verifyParams({
      title: { type: 'string', required: false },
      description: { type: 'string', required: false }
    })
    await ctx.state.question.update(ctx.request.body)
    ctx.body = ctx.state.question
  }
  async checkQuestioner (ctx, next) {
    const { question } = ctx.state
    if (question.questioner.toString() !== ctx.state.user._id) { ctx.throw(403, '没有权限') }
    await next()
  }
  async delete (ctx) {
    await Question.findByIdAndRemove(ctx.params.id)
    ctx.status = 204
  }
}

module.exports = new QuestionsCtl()